1. Field of the Invention
The invention relates to a method and apparatus for a network device that resolves routing congesting problems caused by concurrent MIB status reports received from multiple assembly lines in a channelized switch system.
2. Description of the Related Art
Network management is required to handle special activities of initialization, termination, and monitoring of activities of devices within a network. Typically, network management is viewed as a distributed application which interacts with other management processes in the network to track packet transmission events in order to provide a basis for statistical analysis of the network operation with respect to each data network switch port. The network-management system typically consists of a manager, which executes the managing process. For example, the number of transmitted packets, received packets, and transmission collisions can be counted and polled periodically. These significant parameters, termed objects, are collected in a MIB, which is a collection of managed objects. Namely, objects are variables that hold information about the state of some process running on a network device or that include textual information about the device, such as a name and description. The managed object provides a means to identify, control, and monitor a network device. An agent resides within the local device, collects information from the managed objects and provides that information to the MIB. In essence, agents monitor for significant events that occur within a device. Alarms provide alerts when predefined thresholds are exceeded. Alarms can alert an administrator when defined events occur on the network. Events provide a way to trigger actions based on alarms. Events are defined in MIB modules and are usually based on thresholds that have been exceeded, such as when traffic on a segment of the network has exceeded a particular level. The managed devices themselves are responsible for initiating the alarms, and an agent running on the device traps the event and sends a report to all management stations within the network.
Thus, the MIB specifies the different counters, status events, alarms, and notification to be reported for each managed device. The MIB may be different for different devices contained within the network. Through the use of statistical counters, a determination of an improperly functioning device can be made, such as a device that is generating a loss of data packets. The MIB counters contains all the per port statistic which are updated periodically by the network device.
Depending upon the network management protocol employed, the network management console must continually or periodically poll the agents to obtain information and store the information. A Simple Network Management Protocol (SNMP) is an example of a protocol that requires continual polling, and Remote Monitoring, (RMON) is an example of periodic polling. Nevertheless, the process of gathering this information not only increases network traffic. It also places a large burden on the network management console. In a channelized switch system, such as a SPI-4 (System Packet Interface Level 4) interface, generating MIB events becomes a nontrivial task. The problem occurs due to the fact that the SPI-4 interface is channelized. An unchannelized interface is a single port where all traffic is packet based, so that one packet has to finish being processed before the process for the next packet can begin. However, within a channelized network, multiple packets can be interleaved and transferred simultaneously, up to the maximum number of available channels. For this reason, separate assembly line logic may be needed for each channel to handle all the interleaved traffic being transmitted from the different channels. For example, in a 24-channel SPI-interface, twenty-four individual assembly logic are included to handle the assembly of the data packets as the data is received into the network. Therefore, each assembly line generates a sixty-one-bit wide MIB status event that needs to be processed by the MIB logic to increment the MIB counters. With twenty-four channels transmitting a total of one thousand four hundred sixty-four bit wide status entering into one central location for processing, this can cause tremendous amount of routing congestion. This situation can be further exacerbated because due to the inherent nature of some of today's systems, such as the SPI-4 interface, which are capable of generating, not just one MIB event, but at least two MIBs events which need to be processed simultaneously. Thus, an additional burden is placed on the central MIB processing unit since it is required to process two MIB event statuses with only one set of MIB counters. Although modifying the existing systems to include two sets of MIB logic to handle the two simultaneous status reporting events appears to be an instinctive, straightforward resolution to this problem. However, such a system would endure an unbearable routing congestion problem.
Therefore, a need exists to provide a data path structure for a multi-channel MIB processing unit that is capable of efficiently handling and processing the incoming status events.